This invention relates generally to systems for determining the position of a source of radiation, and more particularly, to a system which employs a plurality of photodetectors for producing an electrical output signal which is responsive to the position of a source of light, with respect to the photodetectors.
Of the numerous known systems for producing electrical signals having information content responsive to the relative orientation of a light source, most are complex and expensive, and have associated therewith electronic signal analysis systems which are bulky, thereby limiting their applicability in space-restricted environments, such as the interior of motor vehicles.
One known arrangement for determining the position of a source of incident radiation utilizes a pair of solar cells arranged in orthogonal relationship to one another. Thus, this system cannot be employed in applications requiring flatness or compactness of the sensor arrangement. The incident electromagnetic radiation, or sunlight, causes the orthogonally arranged radiation detectors to generate respective output electrical signals having amplitudes responsive to the angle of incidence of the light. Ratio-detecting circuitry is used to determine the angle of incidence with respect to the orientation of the solar detectors, by monitoring and comparing the output signals of the respective solar detectors.
A further known system for determining the direction of incident radiation utilizes a sensor head having a hemispherical convex surface area on which are terminated a plurality of optical fibers. The optical fibers are bundled and terminated at their distal ends with detectors, which are arrayed illustratively in the form of a matrix. This known system, however, in addition to requiring a multiplicity of detectors arranged in a matrix, also requires complex mathematical and evaluation circuitry which render this known system unsuitable in applications where simplicity and economy are required.
In vehicles which continually are changing their orientation with respect to the sun, it is desirable to modify the output of associated heating and cooling systems so as to take into consideration the effects of sunlight. In such systems, however, there is not often available space for a complex, multi-component sensor and its associated computation circuitry. There is therefore a need for a sensor which is responsive to the position of a light source, and which also is compact and reliable.
It is, therefore, an object of this invention to provide a system for determining the position of a source of incident radiation which is simple and inexpensive, and does not require a mechanical system to track the source. It is another object of this invention to provide a system for monitoring the position of a light source wherein the detectors can be arranged to be coplanar with one another to achieve compactness and simplicity of manufacture.
It is also an object of this invention to provide a system for monitoring the position of a light source which has substantially flat, coplanar light inputs to the sensors, and wherein a simple current ratio determination can be used to indicate the location of the source.
It is a further object of this invention to provide a system for monitoring the position of a light source wherein an output electrical signal is responsive to an angle of elevation of the light source with respect to a predetermined horizon.
It is additionally an object of this invention to provide a system for monitoring the position of a light source wherein an output electrical signal is responsive to a predetermined azimuth angle.
It is yet a further object of this invention to provide a system for monitoring the position of a light source wherein fiber optic elements are not needed for directing the light to be monitored to a detector.
It is also another object of this invention to provide a system for monitoring the position of a light source wherein a high degree of compactness is achieved.
It is yet an additional object of this invention to provide a system for monitoring the position of a light source, the system being particularly suited for mobile applications.
It is still another object of this invention to provide a system for determining the position and intensity of a source of incident radiation which is simple and inexpensive, and does not require a feedback arrangement.
It is yet a further object of this invention to provide a system for determining the position and intensity of the sun, which does not require a plurality of light-receiving surfaces at different orientations.
It is also a further object of this invention to provide an arrangement for controlling a mobile cooling system in response to the angle of incidence of sunlight.
It is yet an additional object of this invention to provide an arrangement for controlling a mobile cooling system in response to incident sunlight being within a predetermined range of angles of azimuth.